Punch mechanism for buttonholetype sewing machines



Nov. 29, 1938. A. R. VV-OOD 2,138,776

PUNCH MECHANISM FOR BUTTONHOLE-TYPE SEWING MACHINES Filed Sept. 17, 1937 3 Sheets-Sheet l Gum;

Nov. 29, 1938. A R WOOD 2,138,776

PUNCH MECHANISM FOR BUTTONI-IOLE- TYPE SEWING MACHINES Filed Sept. 1?, 1937 s Sheets-Sheet 2 i t I, I i

gwwmw v Alfi ed R. (1/0005 WMweoo NOV. 29, 1938. R WOOD 2,138,776

PUNCH MECHANISM FOR BUTTONHOLE-TYPE, SEWING MACHINES Filed Sept. 1'7, 1937 3 Sheets-Sheet 3 arm,

Patented Nov. 29, 1938 UNITED STATES PATENT oFFicE PUNCH MECHANISM FOR BUTTONHOLE- TYPE SEWING MACHINES Application September 17, 1937', Serial No. 164,265

9 Claims.

This invention relates to sewing machines, more particularly of the buttonhole type used for sewing around buttonholes, eyelets, etc.

Machines of this type are commonly provided with a punch-mechanism for cutting, in the work-material, buttonholes or eyelet holes around which overedge stitches are laid by the stitch-forming mechanism of the machine.

The punch-mechanism of a sewing machine of the buttonhole type commonly comprises a pair of pivoted levers one of which carries an anvil or cutter-block to support the material for the action of the sharpened lower end of a tubular punch-element carried by the other lever.

It has always been a problem to satisfactorily dispose of the punchings or small fragments of material which are cut from the work and collect in the tube of the punch-element of the mechanism. These punchings cannot be allowed to be freely discharged at the upper end of the punch-tube, as they will fall onto the work within the field of operations of the stitch-forming mechanism and may be sewed into the work and mar its appearance.

In order to lead the punchings away from the field of operations on the work, it has been the practice to provide the punch-carrier lever with a punchings-passageway extending lengthwise of r such lever and in communication with the upper end of the punch-tube; a laterally extending discharge tube forming a continuation of the punchings-passageway being mounted on the punch-carrier lever to discharge the punchings over one side-edge of the machine-bed. The difficulty with this arrangement is that the punchings often clog the passageway and the attention of the operator is frequently required to clear the stoppage.

The present invention has for an object to provide automatic means for preventing clogging of the punchings-passageway in the punch-mechanism of a sewing machine of the buttonhole type.

Another object of the invention is to provide for the ready interchangeability of punches of diiferent sizes, without affecting the operation of the present anti-clogging means.

With the above and other objects in View, as 50 will hereinafter appear, the invention comprises the devices, combinations and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

Fig. 1 of the drawings is a side elevation, partly in section, of an eyelet-sewing machine of the buttonhole type embodying the invention. Fig. 2 is a side elevation, partly in section, of the punch-mechanism of the machine; the punch being closed. Fig. 3 is a top plan View of the parts shown in Fig. 2. Fig. 4 is a left end elevation, partly in section, of the parts shown in Fig. 2. Fig. 5 is a section on the line 5-5, Fig. 2. Fig. 6 is a section on the line 66, Fig. 2. Fig. '7 is a disassembled perspective view of a paddlewheel and its carrier used for agitating the punchings and stimulating their movement along the punchings-passageway. Fig. 8 is a perspective view of the star-Wheel alone. Fig. 9 is a section on the line 89, Fig. 2. Fig. 10 is a perspective view of a removable connector tube for leading the punchings from the punch-element to the paddle-wheel and Fig. 11 is a perspective view of the upper punch-lever with the punch and paddle-wheel elements removed.

The present sewing machine is designed to cut a hole in the work and then sew two-thread overseaming stitches around the hole to form an eyelet. Such a machine is constructed with bed 1|, from which rises the standard 2 of the overhanging bracket-arm 3 terminating in the head A.

The stitch-forming mechanism may comprise the usual reciprocatory needle 5, and complementary under-thread mechanism ii mounted to rotate about a vertical axis, as disclosed in the Allen Patent No. 1,162,207; dated Nov. 30, 1915.

The work-clamp comprises the usual lower work-clamping plates l and upper clamping feet 8 which are closed upon the work at the beginning of a cycle of operations and are opened to release the work after the sewing of the eyelet is completed. Such a work-clamp may be constructed substantially in accordance with the disclosure of the Allen Patent No. 1,650,580; dated Nov. 29, 1927.

The punch-mechanism may be of the travelling lever type disclosed in the last mentioned Allen patent and may comprise the upper lever 9 and lower lever 10 each of which is fulcrumed on the screw-pin H carried by the travelling fulcrumcarrier-block l5 transversely slidably dovetailed into the punch-lever 9. The adjusting screws E5 control the position of lateral adjustment of the punch-tube while the set-screws 15 releasably hold the punch-tube l5 in adjusted position in the block !5'.

The punch-mechanism is actuated by the usual cutter-shaft l? which, at the beginning of a cycle of operations, makes one complete rotation and then comes to rest, after which the stitchforming operation is started. The cutter-shaft carries the usual cutter-advancing and -retracting cam i8 which actuates the follower link i9 connected to the rearward extension Zl) of the travelling fulcrum-block l2. This cam shifts the punch-niechanism from initial retracted position to a position in register with the stitch-forming mechanism where the punch is closed by the action of the usual cams 2i 2| upon the respective levers 9 and Ill. As soon as the hole is cut, the punch is opened and retracted to its initial position.

Mounted in the longitudinally extending slot 22 in the top of the upper lever 9, Fig. 11, is the carrier block 23, Fig. 7, between the forwardly extending spaced arms 24 of which the paddlewheel 25 is journaled on the cross-pin 26. The carrier-block 23 is cut away below the arms 24 to provide the laterally inclined guide wall 2i which leads to the lateral discharge opening 28 in the side wall of the upper cutter lever 9. A discharge tube 22 is screwed to the lever 9 to carry the punchings away from the stitch-forming mechanism and discharge them over the edge of the machine bed. The paddle-wheel 25 has a plurality of radial arms or paddles having flat front faces 25, Figs. 6 and 8, which are inclined in a direction to cam or urge the punchings toward the discharge opening 28 in cooperation with the reversely inclined rear wall 2'! of the block 23, Fig. 6.

The open upper end of the punch-tube l5, Fig. l, is enlarged to receive the lower end of the connector tube 36 formed at its upper end with spaced cheeks 3! having broadly convexed outer faces 32 designed to fit against the side walls of the slot 22 in the punch-carrier lever 9 while permitting a limited lateral adjustment of the punch-carrier-block l5 and punch l5 in the lever 9. The cheeks 3i have inclined edges 33 which abut or engage the inclined forward edges 2 3, Fig, 7, of the arms 24 of the paddle-wheel carrier-biock 23 as shown in Fig. 2. The connector tube is releasably maintained in operative position by means of the leaf-spring latch 34 which is secured to the block 23.

Ihe agitator or paddle-wheel 25 is preferably actuated automatically by the travelling movement of the punch-lever fulcrum-block I2, as follows: Mounted on the machine bed by the screw 35 is the foot 35 of a post 3? having pivotally mounted thereon at $8 the upper end of a link 39. Pivotally connected at M3 to the lower end of the link 39 is the rear end of a push-rod 4! which is guided at its forward end in a slot 42, Fig. 7, in the block 23. The push-rod 4! is retained in the slot 42 by means of the overhanging retainer 35, Fig. 9. The spring 44 which bears down upon the push-rod ll retains the front end of the push-rod in position, Fig. 2, to engage and move the paddle-wheel when the punch-mechanism travels from its forward position in register with the stitch-forming mechanism to its initial or retracted position shown in Fig. 1. The inclined blades of the paddle-wheel 25 are formed in their rearward faces with grooves 25 to receive the end of the push-rod ll and avoid any tendency for the inclined blades to cam the end of the push-rod laterally and cause jamming.

In the retracting movement of the punchmechanism, the paddle-wheel 25 is turned one step by the engagement of one of its paddles with the end of the push-rod 4|. At the completion of one step of turning movement of the paddlewheel 25, the end of the push-rod 4-! rides over the top of the engaged paddle-wheel blade, Fig. 1; the-spring 44 allowing the push-rod ll to rise by a swinging movement about its pivot All. The spring 44' is strong enough to operatively maintain the link 39 in engagement with the forward stop 45 on the post 31 when the paddle-wheel 25 is being moved by retraction of the punch-mechanism. The push-rod 4| and link 39 may, however, yield to an abnormal pressure against the end of the push-rod 4! in the remote contingency that the wheel 25 becomes clogged. The rearward stop-pin 56 on the post 31 will permit the link 39 to move far enough to avoid jamming and possible breakage of parts. Retrograde motion of the paddle-wheel 25 is prevented by the spring pawl 47, Fig. 2, which engages the paddlewheel blades.

The fast action of the paddle-wheel 25, during the retraction of the punch-mechanism from sewing position to initial position, forceably throws or propels the punchings along the passageway. Tests have fully demonstrated the efficacy of the device for the purpose intended.

Obviously, the punch l5 and connector tube 3!] may be readily removed and replaced by similar elements for punching holes of different sizes.

The invention is not to be understood as limited to the details of construction and relative arrangements of parts shown and described as various modifications may obviously be made by those skilled in the art within the spirit and scope of the invention.

Having thus set forth the nature of the invention, what I claim herein is:

1. In a sewing machine of the buttonhole type, the combination with stitch-forming mechanism and a workclamp, of punch-mechanism including a punch-lever having a passageway for the punchings, a sharp-ended punch-tube carried by said punch-lever for cutting the punchings from the work and delivering them to said passageway, and means in said passageway beyond the delivery end of said punch-tube and movable relative to said lever to engage the delivered punchings and move them along said passageway toward a discharge point remote from the stitchforming mechanism.

2. In a sewing machine of the buttonhole type, the combination. with overedge stitch-forming mechanism and a work-clamp, of a punch-mechanism including a sharp-ended punch-tube, a punch-tube carrier having a passageway for the punchings cut from the work by said punch-tube, said passageway having a discharge end remote from the stitch-forming mechanism, and means mounted in said passageway to move the punchings toward said discharge end.

3. In a sewing machine of the buttonhole type, the combination with stitch-forming mechanism and a work-clamp, of. punch-mechanism. including a punch-lever having a passageway for the punchings leading to a discharge point remote from the stitch-forming mechanism, an agitator pivoted in said passageway, and means to move said agitator about its pivot to engage the punchings and move them along said passageway.

4. In a sewing machine of the buttonhole type, the combination with stitch-forming mechanism and a work-clamp, of a travelling punch-mechanism movable from a retracted idle position to an advanced punching position and return, said punch-mechanism including a pivoted punchcarrying lever having a punchings passageway, and means actuated by the travelling movement of said punch-mechanism for moving the punchings along said passageway 5. In a sewing machine of the buttonhole type, the combination with stitch-forming mechanism and a work-clamp, of punch-mechanism including a punch-lever having a passageway for the punchings leading away from the stitch-forming mechanism, an agitator pivoted in said passageway, and a push-rod arranged to actuate said agitator.

6. In a sewing machine of the buttonhole type, the combination with stitch-forming mechanism and a work-clamp, of punch-mechanism including a punch-lever having a passageway for the punchings, a paddle-wheel pivoted in said passageway, a pusher to actuate said paddle-wheel in one direction, and means to prevent retrograde movement of said paddle-wheel.

'7. In a sewing machine of the buttonhole type, the combination with stitch-forming mechanism and a work-clamp, of punch-mechanism including a punch-lever having a passageway for the punchings, an agitator carrier removably mounted in said passageway, an agitator mounted on said carrier, and means to actuate said agitator.

8. A punch-mechanism for sewing machines of the buttonhole type having, in combination, a punch-tube having a sharp cutting end, a carrier for said punch-tube having a discharging passageway to receive the punchings from said punch-tube, and means in said passageway to agitate the punchings therein and stimulate their movement to the discharge end thereof.

9. A punch-lever having a punchings passageway, a sharp-ended punch-tube adjustably carried by said punch-lever, a connector-tube leading from said punch-tube to said punchings passageway, a punchings-agitator in said passageway adjacent the discharge end of said connectortube, and means to move said punchings-agitator relative to said punch-lever.

ALFRED R. WOOD. 

